No output color on WS2812b strip for a specific RGB value

I have wired 30 addressable LEDs to a NodeMCU microcontroller. It is powered by a 5v 2amp PSU with a 1000 uf capacitor. The LEDs are at 1% brightness.

I am using #include <Adafruit_NeoPixel.h> and the code to write the color is as follows
uint32_t color = strip.Color(rCurr, gCurr, bCurr);
strip.setPixelColor(i , color);
strip.show();

I am trying to move through a range of colors
I start at (55, 63, 135) and it lights up blue
I move through a few other colors fine
When it gets to (113,66,120) all LEDs go off.
It then changes to (142,76,104) they all turn back on.

Is there a reason all LEDs would turn off at RGB (113,66,120)??

Thanks in advance

This seems to be a problem with brightness... at 1 brightness (113,66,120) shows no color. At 10 brightness it does.

I think that's a good hypothesis.

What the brightness control does, with ws2812 LEDs, is reduce down the r, g, b numbers in your sketch before sending them out to the strip. The minimum value that can be sent which is not off is, of course, 1.

The colours you mentioned which result in the LEDs switching on have at least one channel with a value of at least 135. The colour which switches the LEDs off has a highest channel value of 120. So maybe some value between 120 and 135 is the point where, after the brightness adjustment, the value that gets sent to the strip changes from 0 to 1. I've got a feeling that threshold will be between 127 and 128 :wink: